Mechanical performance of cement– and screw–retained all–ceramic single crowns on dental implants

Abstract

Objectives

This in-vitro study was performed to compare the contact wear, fracture strength and failure mode of implant-supported all-ceramic single crowns manufactured with various fabrication and fixation concepts.

Results

Mouth-motion fatigue testing caused two abutment fractures (SST group and SZL group) and two chipping events (CZL group). Specimens of MZL group showed statistically significant less contact wear compared to the other groups (p<0.001). There was no statistical difference between the groups in terms of the maximum fracture load. SEM-analysis showed a more homogenous structure and surface of CAD/CAM fabricated specimens towards manually veneered components.

Conclusions

The mode of retention did not influence the fracture resistance but the failure patterns of the specimens. CAD/CAM milled lithium-disilicate crowns seemed to be a preserving factor for dental implants.

Clinical relevance

The mode of retention and veneering influences the mechanical performance of implant-supported single crowns.